Radiotelegraphy



H. F. ELLl0TT. RADIOTELEGRAPHY.

APPLICATION FILED JULY 24,1920.

1,399,945. Patented Dec. 13, 1921.

2 SHEETSSHEET I.

" ATTOR NEYSQ H. F. ELLIOTT.

RADIOTELEGBAPHY.

APPLICATION man my 24,1920. 1 ,399,945, Patented Dec. 13, 1921.

fzfuzns-snsn 2.

' 11v VENTOR WITNESS fimzzioit M B W wd wzm ATTORNEYS UNITED STATES PATENT OFFICE.

HAROLD F. ELLIOTT, OF PALO ALTO; onnironnrmnss mnon TO AUGUSTUS TAYLOR, OF SAN FRANCISCO. CALIFORNIA.

RADIOTELEGRAPHY.

Specification of Letters Patent.

Patented Dec. 13, 1921.

Application filed July 24, 1920. Serial No. 398.757.

[0 all whom it may concern:

Be it known that l, Hanonn l3. ELLlo'r'r, a citizen oi the United States, and a resident of Palo A to, county of Santa Clara, and State of California, have invented certain new and useful Improvements in Radiotelegraphy, oi? which the following is a spec ification. i

The invention relates to a transmission system on? radio telegraphy and particularly continuous oscillation radio telegraphy, involving variations in antenna inductance.

An object of the invention is to provide a signaling system in which the voltage and current applied to the signaling keys may be regulated.

Another object of the invention is to provide a signaling system wherein the load is equally divided among a plurality of keys, the load on each key being such that sparking is avoided.

The invention possesses other advantageous features, some of which, with the foregoing, will he set forth at length in the following description where I shall outline in full, that term of the invention which I have selected for illustration in the drawings accompanying and forming part of the present specification. in said drawings I have shown one specific form of the system of my invention, but it is to be understood that 5 do not limit myself to such form, since the invention, as expressed in the claims, may be embodied in a plurality of forms.

Referring to said drawings:

Figure l is a diagrammatic representation of a radio telegraphy transmission system embodying my invention.

Fig. 2 is a, diagrammatic representation of one form of loop system of my invention.

Fig. 8 is a sectional elevation of the system shown in Fig. 2.

Fig. l is a sectional elevation of a modilied form of system.

Fig. 5 is a diagrammatic representation of a modified form of system.

Fig. 6 is a diagrammatic representation of a system involving closer coupling of the signaling circuits.

One method of signaling with continuous oscillations consists in varying the antenna inductance, which variation produces a variation in wave length of the radiated wave, and to produce a given percentage change in wave length the antenna inductance must be changed a certain amount. The antenna current through the inductance changed sets up a certain voltage which, multiplied by the antenna current, gives the kilo-volt-amperes to be handled by the key or relay or other signaling instrument. On account of practical considerations, the kilo-volt-aimperes which can be handled by one pair of contacts is limited and hence it is necessary to employ a plurality of pairs of contacts.

In the system of the present invention, I employ a plurality of pairs of contacts and divide the load equally among the pairs of contacts and so adjust the elements of the system that each pair of contacts carries the maximum load possible without sparking. I am, therefore, able to employ the minimum number of pairs of contacts, while maintaining perfect operating condition at each pa1r.

a One form of continuous oscillation transmission system may be represented by a Poulsen are 2, supplied with current from a direct current generator 3, and subjected to a strong transverse magnetic field produced by the coils 4. One side of the arc is grounded and the other side is connected to the antenna 5, through. the variable inductance or loading coil 6. Arranged in inductive relation with the coil 6, and preferably arranged adjacent the lower turn of the coil, .are a plurality of separate loop circuits 7, substantially sector shaped, with the outer part 8 of each loop concentric with the axis of the coil 6 and preferably of the same radius as the coil. Each loop may consist of one or more turns of the conductor and in practice I employ two or three turns, which causes the load on each individual key to be the maximum load possible, without sparking at the contacts. The side 9 of the loops are radially disposed with relation to the axis of the coil 6 and the loops are arranged in overlapping relation. Each loop is provided with a key or pair of contacts 10 and means are provided for opening and closing all of the contacts simultaneously, or substantially so. In the drawings I have shown one contact of each pair connected to a solenoid 11, all of the solenoids being arranged in a circuit containing a battery and a signaling key.

Thephi'rality of loops act as the secondary of a step-down transformer and the voltage in each loop is much lower than the voltage in the loading coil. By arranging the loops in overlapping relation and insulated from each other, current in one loop does not induce current in the adjacent loops and, there fore, the contacts in each loop handle only the predetermined proportion of the load for which they are arranged.

A further advantage of overlapping the loops is that such construction permits each loop to be made larger than if the loops were spaced apart circuinterentially to reduce mutual inductance, permitting each loop to inclose more flux from the loading co l without excessive close coupling.

in the across the terminals of one loop, closing the adjacent loop and then varying the amount of overlapping so that opening and closing of the adjacent loop will not vary the voltmeter reading.

It is desirable to erl'ect a close coupling between the loops and the loading. coil so that the maximum number of lines of force will traverse theloop circuits, but it is also.

desirable to reduce the current load on the key units to maintain it below the maximum non-sparking load. The current load on each'key unit may be decreased, by inserting a resistance 14 in each loop circuit in series with the'key, and the value of the resistance is so adjusted that a reduction in the power delivered to the antenna is obtained when the resistance is eli'ectlve in the circuit. The.

'- percentage of reduction of power is depend main loading inductor.

ent upon the amount of resistance in the loop circuits and upon other electrical rel-a tions between the coupled loops and the The insertion of resistance in the loop circuits not only reduces the current through the key units but also, when the resistance is eiiective decreases the amplitude of the radiated waves and reduces interference from the compensating wave.

i /hen large loading inductors are used, such as those installed in high powerstations, it is sometimes diflicult to obtain the proper coupling between the inductor and the loops, and I have providedmeans for producing better control oi the coupling between these elements. Arranged within the circle of the loops and preferably inthe plane thereof, is a short eircuited turn or loop 15 which is effective in increasing the magnetic flux through the key loops for any given location of the key loops with respect to the main loading inductor. The short circuited loop or winding may comprise single loop or a plurality of turns.

Assuming that the main flux from the loading coil is in a downward direction at a given instant, as shown by the arrows in Fig. 3, a current will flow in the I short circuited winding 15 which will set up a flux through the center of the winding ap proximately in opposition to the flux of the main loading coil. The magnetic flux surrounding theconductor 01 the short circuit ed winding will cut the inner ends of the key loops in the same direction as'the time from the loading coil, thereby increasing the flux through the key loops, providing a closer coupling to the main coil.

WVhen desirable the short circuited turn may be extended upward into the inductor 6 to obtain a variable coupling between the main loading coil and the short circuit winding, as shown in Fig. 4. Connected in series with the short circuit winding 15 is a winding 16 disposed within the coil and which is threaded by he loading coililux. The use of this arrangement makes it possible to regulate the load impressed on the signaling system and gives control of the voltage and current on the key units for any wave-length over the entire range of operation of the transmitting station.

In some instances it may be desirable to connect a variable reactor 1'? in series in the. short circuit winding to regulate the current through it and thereby regulate the load on the keys.

Instead oi coupling the key loops directly with the main loading coil, the primary l8 of an air core transformer may be arranged in the antenna circuit and the key loops may form :the secondary of such transformer. 'l he unit resulting from this construction is an air core alternating current transformer having a secondary winding composed of a to have the same inductive relation to the :primary, but so arranged that the inductive plurality of isolated sector circuits, arranged spaced apart at one point and the key loops inserted between the spaced parts of the coil as shown 1n Flg. 6. The prmclpal advantages oi this arrangement are that the coupling remains more constant over a big variation in wave length of the system and that better control is obtained for the power supply to the key units.

I claim 1. A radio telegraphy transmission system including an antenna circuit, an inductance coil in said circuit, a plurality-of isolated overlappingsector circuits inductively connected to said inductance coil, and means for opening and closing the sector circuits.

2. A radio telegraphy transmission system, including an antenna circuit, an inductance coil in said circuit, a plurality of overlapping isolated circuits arranged 1n the same inductive relation to said inductance coil, and means for opening and closing said isolated circuits.

3. A radio telegraphy transmission system, including an antenna circuit, an inductance coil in said circuit, a plurality of overlapping isolated circuits arranged in the same inductive relation to said inductance coil, the circuit being so overlapped that a current in one coil induces no voltage in the overlapping coil and means for opening and closing said isolated circuits.

4. A radio telegraphy transmission sys tem, including an antenna circuit, an in ductance coil in said circuit, a plurality of isolated overlapping sector circuits arranged in the'same inductive relation to said inductance coil, and means for opening and closing said isolated circuits.

5. A radio telegraphy transmission system, including an antenna circuit, an inductance coil in said circuit, a plurality of overlapping isolated sector circuits inductively connected to said inductance coil, each sector circuit comprising a plurality of turns of conductor, and means for opening and closing said isolated circuits.

6. A radio telegraphy transmission system including an antenna circuit, and inductance coil in said circuit, a plurality of loop circuits inductively connected to said inductance coil, a resistor in each loop circuit and means for opening and closing the loop circuits.

7. A radio telegraphy transmission sys tem including an antenna circuit, an in ductance coil in said circuit, a plurality of loop circuits arranged in the same inductive relation to said inductance coil, a resistor in each loop circuit and means for opening and closing the loop circuits.

8. A radio telegraphy transmission system including an antenna circuit, an inductance coil in said circuit, a plurality of isolated loop circuits arranged in the same inductive relation to said inductance coil, a resistor in each loop circuit and means for opening and closing the loop circuits.

9. A radio telegraphy transmission system including an antenna circuit, an inductance coil in said circuit, a plurality of isolated sector circuits arranged in the same inductive relation to said inductance coil, a resistor in each isolated circuit and means for opening and closing said isolated circuits.

10. A radio telegraphy transmission system including an antenna circuit, an inductance coil in said circuit, a plurality of loop circuits inductively connected to said inductance coil, a variable resistor in each loop circuit and means for opening and closing said loop circuits.

11. A radio telegraphy transmission sys tem including an antenna circuit, an inductance coil in said circuit, a plurality of isolated sector circuits arranged in the same inductive relation to said inductance coil, a variable resistor in each isolated circuit and means for opening and closing the isolated circuits.

12. A radio telegraphy transmission system including an antenna circuit, an inductance coil in said circuit, a plurality oi loop circuits inductively connected to the inductance coil, a short circuited coil inductively connected to said inductance coil and said loop circuits, and means for opening and closing the loop circuits.

13. A radio telegraphy transmission system including an antenna circuit, an inductance coil in said circuit, a plurality of loop circuits arranged in the same inductive relation to said inductance coil, a short circuited coil inductively connected to said inductance coil and to said loop circuits, and means for opening and closing said loop circuits.

14. A radio telegraphy transmission system including an antenna circuit, an inductance coil in said circuit, a plurality of loop circuits arranged in the same inductive relation to said inductance coil, a short circuited coil inductively connected to said in ductance coil and said loop circuits, and means for varying the effect of the loop circuits on the inductance coil.

15. 'A radio telegraphy transmission system including an antenna circuit, an inductance coil in said circuit, a plurality of isolated loop circuits arranged in the same inductive relation to said inductance coil, a short circuited coil inductively connected to said inductance coil and said loop circuits, and means for varying the efl'ect of the loop circuits on the inductance coil.

16. A radio telegraphy transmission system including an antenna circuit, an inductance coil in said circuit, a plurality of circumferentially disposed loop circuits inductively connected to the inductance coil, a short circuited coil arranged Within the circle of the loop circuits and means "for varying the effect of the loop circuits on the inductance coil.

17. A radio telegraphy transmission systein including'an'antenna circuit, an. inductance coil in said circuit, a plurality/of circumferentially disposed loop circuits inductively connectedto the inductance coil, a

short circuited coil arranged Within the circle of the loop circuitsand means for opening and Closing the loop circuits.

-cumferentially disposed loop" circuits arranged in the same indurtive relation to the inductance coil, a short circuited coil arranged Within the circle of the loop circuits and means for opening and closing the loop circuits.

l9. Aradio telegraphy transmissionsystern including .an antenna circuit, an inductance coil in said circuit, a plurality of isolated circumferentially disposed loop cir cuits arranged in the same inductive relation to the inductance coil, a short circuited coil arranged Within the circle of the loop circuits and means for opening and closing the loop circuits.

20. A radio telegraphy transmission systern including an antenna circuit, an inductance coil in said circuit, a plurality of circumferentially disposed loop circuits arranged in a plane perpendicular to the axis of the coil and in the same inductive relation thereto, a short circuited coil arranged with: in the circle of and in the'plane of the loop circuits, and means for opening and closing the loop circuits.

21. A radio telegraphytransmission system including an antenna circuit, an inductance coil in said circuit, a plurality of circumferentially disposed isolated loop circuits arranged in a plane perpendicular to the axis 01 the coil and in the same inductive relation thereto, a short .circuited coil arranged Within the circle of and in the plane of the loop circuits, and means for opening and closing the loop circuits.

22. A radio telegraphy transmission systern including an antenna circuit, an inductance coil in said circuit, a plurality of circumferentially disposed loop circuits arranged in a plane perpendicular to the axis of'the coil andin the same inductive relation thereto, a short circuited Windinghaving acoil arranged Within the circleoi' and in the plane of the loop circuits and a coil arranged within the inductance coil, and means for \arying the effect of the loop circuits on the inductance coil.

23. A radio telegraphy transmision system inchiding an antenna circuit, an inductance coil-in said circuit, a plurality of circumferentially disposed loop circuits arranged in a plane perpendicular to the axis of the coil and in the same inductive relation thereto, a short circuited Winding having a coil arranged Within the circle of and in the plane oi the loop circuits and a coil arranged Within the inductance coil, and means. for opcning and closing the loop circuits.

A radio telegraphy transmission systorn including an antenna circuit, an inductance coil in said circuit, a plurality of loop circuits inductively connected'to the inductance coil, a short circuited Winding having a coil inductively connected to the loop circuits and a coil lying Within the inductance coil, and means :tor opening and closing the loop circuits.

25. ll. radio telegraphy transmission system including an antenna circuit, an inductance coil in said circuit, a plurality of loop circuits inductively connected to the induction coil, a short circuited coil inductively connected to the inductance coil and the loop circuits, a reactor in the circuit of the short circuited coil, and means for varying the eiiect of the loop circuits on theinductance coil.

26. A radio telegraphy transmission system including an antenna circuit, an inductance coil in said circuit, a plurality of loop circuits inductively connected to the induction coil, a short circuited coil inductively connected to the inductance coil and the loop circuits, at variable reactor in the circuit of the short circuited coil, and means for varying the eil'ect of the loop circuits on the inductance coil.

In testimony whereof, I have hereunto set my hand. I

HAROLD F. ELLIOTT. 

